Quantitative improvement of lymph nodes visualization of breast cancer using 99mTc-nanocolloid SPECT/CT and updated reconstruction algorithm

Işıkcı, Nazenin İpek; Abuqbeitah, Mohammad

doi:10.1007/s00411-021-00914-w

Cited by 2 publications

(3 citation statements)

References 12 publications

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“…The noise characteristics, contrast, and CNR were evaluated for each acquisition time using statistics obtained from ROIs in both normal and abnormal areas in bone. 26 , 29 , 30 ROIs were drawn on the hot abnormal bone area identified by the reporting physician. Additional ROIs were delineated over areas of adjacent normal bone guided by the CT boundaries of the fused SPECT/CT images.…”

Section: Methodsmentioning

confidence: 99%

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Optimization of ^99mTc whole‐body SPECT/CT image quality: A phantom study

Alqahtani

Willowson

Constable

et al. 2022

J Applied Clin Med Phys

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Purpose Investigate the impact of acquisition time and reconstruction parameters on single‐photon emission computed tomography/computed tomography (SPECT/CT) image quality with the ultimate aim of finding the shortest possible acquisition time for clinical whole‐body SPECT/CT (WB‐SPECT/CT) while maintaining image quality Methods The National Electrical Manufacturers Association (NEMA) image quality measurements were performed on a SPECT/CT imaging system using a NEMA International Electrotechnical Commission (IEC) phantom with spherical inserts of varying diameter (10–37 mm), filled with 99mTc in activity sphere‐to‐background concentration ratio of 8.5:1. A gated acquisition was acquired and binned data were summed to simulate acquisitions of 15, 8, and 3 s per projection angle. Images were reconstructed on a Hermes (HERMES Medical Solutions AB, Stockholm, Sweden) workstation using eight subsets and between 4 and 24 iterations of the three‐dimensional (3D) ordered subset expectation maximization (OSEM) algorithm. Reconstructed images were post‐smoothed with 3D Gaussian filter ranging from 0 to 12 mm full‐width at half maximum (FWHM). Contrast recovery, background variability, and contrast‐to‐noise ratio were evaluated Results As expected, the spheres were more clearly defined as acquisition time and count statistics improved. The optimal iteration number and Gaussian filter were determined from the contrast recovery convergence and level of noise. Convergence of contrast recovery was observed at eight iterations while 12 iterations yielded stabilized values at all acquisition times. In addition, it was observed that applying 3D Gaussian filter of 8–12 mm FWHM suppressed the noise and mitigated Gibbs artifacts. Background variability was larger for small spheres than larger spheres and the noise decreased when acquisition time became longer. A contrast‐to‐noise ratio >5 was reached for the two smallest spheres of 10 and 13 mm at acquisition times of 8 s Conclusion Optimized reconstruction parameters preserved image quality with reduce acquisition time in present study. This study suggests an optimal protocol for clinical 99mTc SPECT/CT can be reached at 8 s per projection angle, with data reconstructed using 12 iterations and eight subset of the 3D OSEM algorithm and 8 mm Gaussian post‐filter.

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Section: Methodsmentioning

confidence: 99%

“…The noise characteristics, contrast, and CNR were evaluated for each acquisition time using statistics obtained from ROIs in both normal and abnormal areas in bone 26,29,30 . ROIs were drawn on the hot abnormal bone area identified by the reporting physician.…”

Section: Methodsmentioning

confidence: 99%

Optimization of ^99mTc whole‐body SPECT/CT image quality: A phantom study

Alqahtani

Willowson

Constable

et al. 2022

J Applied Clin Med Phys

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“…Our study also showed that for all T/B ratios, COVs were relatively high. This was an inevitable compromise when quantification was the main aim of this study since a larger number of iterations could not only increase quantification accuracy but also increase background noise [47,68].…”

Section: Discussionmentioning

confidence: 99%

Impacts of acquisition and reconstruction parameters on the absolute technetium quantification of the cadmium–zinc–telluride-based SPECT/CT system: a phantom study

et al. 2021

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Background The digital cadmium–zinc–telluride (CZT)-based SPECT system has many advantages, including better spatial and energy resolution. However, the impacts of different acquisition and reconstruction parameters on CZT SPECT quantification might still need to be validated. This study aimed to evaluate the impacts of acquisition parameters (the main energy window and acquisition time per frame) and reconstruction parameters (the number of iterations, subsets in iterative reconstruction, post-filter, and image correction methods) on the technetium quantification of CZT SPECT/CT. Methods A phantom (PET NEMA/IEC image quality, USA) was filled with four target-to-background (T/B) ratios (32:1, 16:1, 8:1, and 4:1) of technetium. Mean uptake values (the calculated mean concentrations for spheres) were measured to evaluate the recovery coefficient (RC) changes under different acquisition and reconstruction parameters. The corresponding standard deviations of mean uptake values were also measured to evaluate the quantification error. Image quality was evaluated using the National Electrical Manufacturers Association (NEMA) NU 2–2012 standard. Results For all T/B ratios, significant correlations were found between iterations and RCs (r = 0.62–0.96 for 1–35 iterations, r = 0.94–0.99 for 35–90 iterations) as well as between the full width at half maximum (FWHM) of the Gaussian filter and RCs (r = − 0.86 to − 1.00, all P values < 0.05). The regression coefficients of 1–35 iterations were higher than those of 35–90 iterations (0.51–1.60 vs. 0.02–0.19). RCs calculated with AC (attenuation correction) + SC (scatter correction) + RR (resolution recovery correction) combination were more accurate (53.82–106.70%) than those calculated with other combinations (all P values < 0.05). No significant statistical differences (all P values > 0.05) were found between the 15% and 20% energy windows except for the 32:1 T/B ratio (P value = 0.023) or between the 10 s/frame and 120 s/frame acquisition times except for the 4:1 T/B ratio (P value = 0.015) in terms of RCs. Conclusions CZT-SPECT/CT of technetium resulted in good quantification accuracy. The favourable acquisition parameters might be a 15% energy window and 40 s/frame of acquisition time. The favourable reconstruction parameters might be 35 iterations, 20 subsets, the AC + SC + RR correction combination, and no filter.

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Quantitative improvement of lymph nodes visualization of breast cancer using 99mTc-nanocolloid SPECT/CT and updated reconstruction algorithm

Cited by 2 publications

References 12 publications

Optimization of ^99mTc whole‐body SPECT/CT image quality: A phantom study

Optimization of ^99mTc whole‐body SPECT/CT image quality: A phantom study

Impacts of acquisition and reconstruction parameters on the absolute technetium quantification of the cadmium–zinc–telluride-based SPECT/CT system: a phantom study

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Quantitative improvement of lymph nodes visualization of breast cancer using 99mTc-nanocolloid SPECT/CT and updated reconstruction algorithm

Cited by 2 publications

References 12 publications

Optimization of 99mTc whole‐body SPECT/CT image quality: A phantom study

Optimization of 99mTc whole‐body SPECT/CT image quality: A phantom study

Impacts of acquisition and reconstruction parameters on the absolute technetium quantification of the cadmium–zinc–telluride-based SPECT/CT system: a phantom study

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Optimization of ^99mTc whole‐body SPECT/CT image quality: A phantom study

Optimization of ^99mTc whole‐body SPECT/CT image quality: A phantom study